Neuroendocrine Neoplasms (NENs)

Neuroendocrine neoplasms (NENs) represent a rare and heterogeneous group of malignancies which can develop in many different sites of our body. They originate from the cells of the diffuse neuroendocrine system. Gastroenteropancreatic NENs were classified in four categories, including NETs G1 (WD with 20% Ki-67), and NECs (PD with >20% Ki-67) in accordance with the 2019 WHO classification (IARC WHO Classification of the digestive system tumors, on 11th July 2019). Lung NENs, in accordance with the latest WHO classification, 2015 edition, are distinguished in small cell lung cancer (SCLC), large cell neuroendocrine carcinoma (LCNEC), atypical carcinoid (AC), and typical carcinoid (TC).